Means of retention and traction for dentures



Feb. 20, 1934. GROVES 1,947,907

- MEANS OF RETENTION AND TRACTION FOR DENTURES Filed Jan. 19. 1931 P lg FTLQ-5I gimme/Mo:

@157 Jay Grams awn/M1013 Patented Feb. 20, 1934 UNITED STATES MEANS OF RETENTION AND TRACTION FOR DENTURES Jay Groves, Seattle, Wash.

Application January 19, 1931. Serial No. 509,828

4 Claims.

My invention relates to dentures, and it has for its object the provision of a means whereby dentures may be held in the mouth with a minimum of discomfort to the wearer, and with a maximum of retention and traction, and to'disclose a technique for employing the same.

It is an object of my invention, in addition to the general objects expressed above, to provide a device employed in the making of such dentures and in such technique which is simpleand inexpensive, and which lendssitself to the construction of varied types, sizes and shapes of dentures, and to various denture materials, to the end that such devices may be of universal application.

My invention comprises the novel denture, the novel method of making the same, and the novel cell employed in the making of such dentures, all

as shown in the accompanying drawing, described,

in the specification, and as will be more particularly defined by the claims which terminate the same.

Figure 1 is a view of the inner or seating sur-- face of adenture, completed in accordance with my method. r

Figure 2 is a plan view of one form of cell, and Figure 3 is a like view of another form.

Figures 4 and 5 are cross sections through the respective forms of cell shown in Figures 2 and 3. Figure 6 is a cross-section through a model of a jaw, and a denture in the process of manufacture, according to my method.

Figure 7 is a cross-section through a denture, made with the cell of Figures 2 and 4, and Figure 8 is a similar view of a denture made with the cell of Figures 3 and 5.

In the practice of my profession of dentistry, I have observed that dentures which employ ridges, peaks and other devices upstanding above the seating surface of the, denture, are extremely uncomfortable, and in addition, the retention and traction thereof are restricted to the area within such upstanding devices, and is usually poor, because of the tendency of the tissues to resume their normal shape, thereby forcing the main seating surface of the denture away from the jaw. It has heretofore been proposed to incorporate special suction or retention devices of softer material, as soft rubber, for instance, but such devices offer a convenient harbor for germs which set up irritation, and which are the cause of an unhealthy condition of the mouth, and in addition, they do not help the retention or traction, since they are subject to the same objections as the hard devices in this respect.

According to my invention, the denture, generally indicated by the numeral 1, is provided upon its inner or seating surface with one or more well defined depressions 3 of appreciable area, which area lies generally below the seating surface 2, thus forming in the denture itself, and of the same material, suction cups. which primarily cause retention of the denture, owing to the tissues of the mouth fitting within these cup depressions and sealing the same, creating a vacuum or suction effect. When the denture is first placed in the mouth, the tendency of the tissues is to resume their natural shape, and this tends to withdraw the tissues from the suetion cups thus created, and draws the seating surface closer to the jaw because of the depression of the area within the cups, thus creating suction which retains rather thanrejects the denture. As the mouth becomes more accustomed to the denture, however, the 'mouth tissues remain shaped to fit within the suction cups and lie closely to the surface within these cups. To heighten the suction effect under such circumstances'I may employa very slightly raised rim or bead 4 defining the edge of the depression 3 and upstandingslightly above the seating surface 2, Its function is to increase the depth of andto more sharply define the depression, since the thickness of the denture, and hence of the depression, cannot be great. Thus the suction effect of the depression is increased, although under some conditions it may be found desirable to omit the. bead 4.

In order to increase the suction effect, and'more particularly to gi'vebetter traction between the tissues of the mouth andthe denture, I provide a group of knurled peaks 5 which stand up above the general level of the depression 3, but which are preferably not quite as high as the general level of the seating surface 2. Because the de pression is shallow they cannot stand up greatly, and hence will not sharply indent the tissues or cause discomfort. 7

By such means as this, the suction effect is created primarily by the depression 3, assisted, when the bead 4 is employed, by the latter, and the traction is created by the interengagement of the mouth tissues and the peaks 5, the tissues being forced from the outset into engagement with the peaks, and yet not with sufficient force to injure the tissues or to cause the user discomfort, since the depressions are more or less shallow and operate because of the multiplicity of the points of engagement rather than by the severity of any one point.

A number of such depressions may be employed,

lit

the knurling of the area within the depression,

and this must be of such area as to give in the aggregate an adequate traction effect. Again, the greater portion of the seating surface of the denture should be smooth, since this will give greatest comfort to the wearer. It is desirable, because of these considerations, that several independent depressions be employed, rather than that the suction area, or any traction area, should extend gen erally over the entire seating surface.

Different sizes and shapes may be employed, and they will be placed generally upon the inner curve of the denture, or at such places as experience will show will obtain the best results in mouths having given characteristics. They may be employed to equal advantage in lower plates,

in upper roof plates, in roofless upper plates, and in partial plates.

As may be seen best in Figure 8, I may provide a groove 6, which extends about the margin of the depression 3, this serving to heighten the suction effect of the depression and to permit slightly increased traction between the peaks 5 and the mouth tissues, and acting as a seal about the knurled area, thus heightening its suction effect.

In the formation of such depressions, I prefer to employ an element of pliable metal, such as the disk shown in Figures 2 and 3. The shape, as I have already mentioned, may be varied to suit conditions, but for purposes of illustration} have shown a circular disk. Such a disk may be made of metal containing lead, or other material which makes it pliable, so that, while it may be supplied in substantially flat, or slightly dished form, it may be bent and shaped by the dentists fingers to fit the contour of the mouth.

Such a disk 11 is shown in use in the process of making a denture in Figure 6. According to this process, there is made a model of the mouth, indicated at 20, and upon the outside of this model there is fitted a disk or disks 11, these being suitably held to the surface of the model after the model 20 has been completely formed. This may be accomplished by inserting a brad 21, or the like, through the soft metal cell and into the model 20.

denture 1 may immediately be molded about this model thus formed, but I prefer, in order to form the head 4, that the material of the model (usually of plaster of Paris) be removed with a sharp point to leave a slight groove, indicated at 22, immediately about the edge of the disk 11. Now, when the denture is formed by molding the plastic material about the model 20 with its applied disks 11, the material flows into the groove 22 and forms the bead or rim 4, while the disks 11 fit within the denture and may be separated from the model along with the denture.

Upon separating the cell 11 from the denture, after the latter has been molded and hardened in the usual course, or before, if desired, there re mains the depression 3 in the denture, having the knurling or peaks 5 which corresponded to the depressions 15 of the cell 11. In the form shown in Figure 2, the depressions of the cell, arranged in'rows at right angles to each other to form a compact knurled group, merge into the general level of the cell at its edge, but in Figure 3 there is provided an upstanding rim 16 about the edge of the cell, which in use forms the shallow groove 6, as seen in Figure 8. This is a further means of acoentuating the definition of the margin of the depression, and hence acoentuating its suction effect.

What I claim as my invention is:

' 1. A denture having a depression in its seating surface, a groove Within and about the margin of the depression, and below its general level, and. a group of peaks slightly upstanding inside of said groove within the depression.

2. A denture having a depression in its seating surface, abead slightly upstanding from the seating surface and immediately about the edge of the depression, a groove within and about the margin of the depression, and below its general level, and a group of peaks upstanding inside of said groove, the general surface of said peaks lying well below the edge of the depression.

3. A dental plate having a suction chamber in its contact surface, such chamber comprising a substantially circular depression, a knurled traction surface molded in the bottom of the depression, and a marginal groove formed below the generalbottom level of the depression.

4. A cell for use in the making of dentures comprising a thin imperforate disk of pliable metal having impressed in one surface peak-forming depressions disposed in crossed rows, and a rim upstanding from the general surface about the edge of the disk.

55 Thus there is formed a model having upraised from its surface the thin metal disk 11, and the JAY GROVES. 

